Tire-pump.



NN NN 2 SHEETS-SHEET 2 Patented Apr. 18, 1916.

H. F. MOLKENBUR.

TRE PUMP.

APPLICATION FILED MAY 3, i915. A793549 HUUR/V575 HENRY F. MGLKENBUE, OF ST. PAUL, MINNESOTA.

TIRE-PUMR Application filed Hay 3, 1915.

To all whom t may concern Be it known that I, Hmm li. Monsun- BUR, a citizen of the United States, and a resident of St. Paul, in the county of Ramsey and State of Minnesota. have invented certain new and useful Improvements in Tire-Pumps, of which the following is a specification. Y

My invention relates to air pumps, and one of the main objects thereof is to provide a pump adapted for connection with pneumatic vehicle tires which will autoniatically maintain the air within a tire at a desired pressure by taking advantage of the variations from mean pressure while a vehicle is being driven over the usual road inequalities.

My invention is fully described in the following specification, of which the accompanying drawings form a part, in which like characters refer to like partsdn each of the views, and in which Figure 1 is a vertical section taken through a pneumatic tire provided with my autoV matic pump, on the line 1-1 of Fig, 6, with the parts in extreme outer positions; Fig. 2 is a. similar view taken on the line 2-2 of Fig. 7, with the parts in innermost positions;

Fig. 3 is a section taken on the line '3f-3 of Fig. 1; Fig. 4 is a section taken on the line 4-4 of Fig. 1; Fig. 5 is a plan view of a fabric strip and a spring which I employ; Fig. 6 is a section taken on the line 6-6 of Fig. 1; Fig. 7 is a section taken on the line 7-7 of Fig. 2; 8 is an enlarged, fragmentary, section of the pump mechanism; und Fig. 9 is a view similar to Fig. 6 but Showing a modification thereover. A

In the drawings forming apart of this application' I have shown a fiortion of an automobilewheel consisting f4 a felly 10 having a rim '11 thereon for h lding a shoe 12 within which is an inner tube 13, a bore 14 being provided through the felly and rim. and a hole 15 through the inner tube.

AIn the form shown in Figs. 1 to 8, inclusive, I pass a shell 16 through the bore 14, said shell having a base plate 1T at its outer end restingupon the rim 1l and is screwthreaded externally to receive a 'detachable cap 18 having a larger bore 19 for the greater part of its length and a bore 2G of lesser diameter' at its free end, saidcap also having an externally threaded extension 2l thereon and an internal shoulder 22 formed by means of pins, screws, or in any suitn Specification of Letters Patent.

Patented Apr. 18, 1916.

serial No. 25,433.

11 and inner tube 13 and serving, also, as

supports for the ends-of a plate or leaf spring the normal tendency of which is to be outwardly convexed as shown in Fig.

T. but which yields under pressure and is capable of assuming the position shown in Fig. 6. and I provide a stri or pad 26 between the spring and the inner tube 13 to prevent injury to or wear on the latter, this strip or pad being preferably of fabric.

Secured in any desired manner to the spring Q5 and passing perpendicularly therey through is a tube 27 which also passes through the hole 15 in the inner tube and is provided with a flange 28 within said tube locking the inner tube, the spring, and the interposed pad 26 together in such'manner as to preventleakage of air at the holel, the tube 27, spring '25, and this portion of the inner tube 13 thus being movable las a unit. M v

The tube 2T is ofcqnsiderably less diameter than that.y of the shll and projects entirely therethrough, thef-ree end thereof having small notches 29 cuttherein and also having a valve 30 therein adapted to be opened inwardl of the tube 27 against` the action of a coi -spring 3l. this being most clearly shown in Fig. 8.

Finch-cling the free end of the tube 27 is a sleeve 32 forming a part of a. flanged piston member 33 fitting closely in the cap 18 and having a port 34 therethrough controlled by .a flap valve 35 opening toward and into the tube 27; also forming a part of this member 33Y is a cylinder 36 having a. similar flanged member 37 on its opposlteend pro'- vidcd with a port 38 controlled by, a fla valve 39 opening int'o the cylinder 36, an I interpose a coil s 'ring 40 between the cap shoulder 22 an the flanged' member 33 which operates to maintain the member 33 and connected parts in constant contact with the free end of the tube 27.'

I interpose a rolling washer 4L between the interior of the cap 18 and the exterior of the cylinder 36, a. .similar washer 42 betwer the sleeve 32 and the interior of the cap, and a similar washer 42 between the interior ofthe shell 16 and the exterior of the tube 27, these washers being rings of round rubber rolling with the contactin,, r elements as they move with res ct to each other and serve to prevent air rom passing Afrom one side of each washer to the other side. It will be noted that all the valves open toward the interior of the inner tube. 13, to draw air intosaidtube in a manner now to be described.

yThe normal positions of the parts with the inner tube deflated are as shown in Fig. 7, and I may connect the conventional tire pump with the externally threaded extension 21 and inflate the tire in the usual inanner until a desired pressure is attained. It' this pressure exceeds the strength of the leaf spring said spring` is forced into a position of less curvature, possibly flattened into the position shown in Fig. (i, thereby moving the tube 27 toward the open end of 'the cap 18 and forcing the cylinder 36 toward said cap end against the action ot' the coil spring 40. This tends to prevent inward opening of the flap valve 23 and further pumping is unnecessary, the parts re1naining in these positions as long as this pressure in the inner tube is maintained. However, should leakage occiir, the leaf spring 25 and coil spring 4() tend to move the parts toward their normal positions and a curvature of the leaf spring results in the degree of lessened air pressure within the inner tu'be and a corresponding degree of play is possible to the leaf spring and connected parts I lVith the parts in their relaxed or partially relaxed positions due to loss of pressure within t-he tire, it being assumed that the vehicle on which my pumps are mounted is moving over a road or the like, it' thev tireis suddenly compressed by striking a stone or other inequality in the road the air pressure within the tireis correspondingly increased and, when the inequality has been passed and the tire again expands into normal position this temporary excess pressure is again lowered to the normal or mean pressure. When the tire was first comv pr'essed by such road inequality, the leaf spring 25 lwas correspondingly moved from normal position, thus forcing the tube 27 and cylinder 36 toward the flap valve 23 and which was closed thereby, the air within thellcap adjacent said valve 23 being.

forced into the cylinder 36, the flap `valve 39 opening to permit its passage; when the tire resumed its normal condition, air again passed the fla valvev23 by reason of the fact that the ea'f spring had again drawn the tube 27 inwardly and permitted the coil spring 40 to correspondingly move the cylnder 36. Repeated leaf spring actuations because of. road inequalities tend to fill the cylinder. with air and to compress the air therein in slight degree, the air being allowed to pass the flap valve 35 into the space 43 between the washers 4l and 4'. through the nhtchcs 29, it being assumed that this air is not of suilicient pressure to overcome the spring valveJ 3U in thc tube 2T. However, many such leaf springr movements cause the air to bc compressed in the space or chamber 43 until the rcsistancc ot' said valve 3() is overcome. after which excess air passes to the inner tube, and this continues until the pressure within the inner tube 13 is again sufficiently strong to again force the parts into the positions `shown in v["ig. wherein there is no leaf spring movement and no air being admitted.

In ["ig. 9 is shown a simplification of the structure already described, this modification employing a similar lcat' spi-iinr 25, I

pad '26, and tube 27, with the difl'crcncc that the said tube. 27 is flanged at its free end as shown at -H to fit closely the interior of thc free end of the shell lf, much longer in this i'orm. and said shell has a coil spring l5 tliei'eiii,arouiid the tube 27, bearing between a member 4G on the interior ofl said shell and the said spring 25, and l also providil a rolling` washer 47 in the space 4S bctwceu the member JAS and the tube flange 44.

The air within the cap is locked therein when the tube Q7 is forced toward l,the cap end by means ot the flap valve "23 andis forced through the tube. valve 3() to the` inner tube 13. this air movement being di- .rect and being applicable to light vehicles.

whereas the air movement in the first form is indirect and entry to the` inner tube occurs on the return of thc parts to normal *positions instead oi'. as in thc second form. .on the niovefncnt ot' thc parts from normal positions.

ln either forni thc automatic )umping begins as 'soon as the pressure within the inner tubc of the tire falls below the strength ot' the leal spring 25 and coil springs cooperating therewith, and pumping continues until the pressure in the tire exceeds the strenfgth of the said springs, at which time the ap "alve 23 in the cap is closed.

My invention is very simple inconstrucand in installatitin, and requires no alteration in the conventional wheels or tires; it does not interfere with the conventional methods of tire inflation, and presents the same outward a pcarance as the presentvalves and caps tlierefor; it may be readily installed by an unskilled person, and it requires no care or attention after installation, except in the event of a puncture or blowout; the device is com aratively inexpensive, and is well adapte to the pur ose for which it is designed, beinlg preferably Amade o' sufficient capacity to ta e care of ordinary leakage around the valve or even small fpunctures, thus permitting ruil enjoyment in' riding` in a vehicle so provided, exce t incas of.accidentel I may. employ a tu '1 49 to prevent Vdirt or water getting into the tire, or I may'empl'oya suitable screen over the ort 20,'if`desired. i* avin fullyy described niyv invention, what I c aim as new, and desire to secure by Letters Patent; is z-- l. The combination with aveliicle wheel 'having a felly, of a tire formed of an annular air tube, a ump .in operative connection with said lie ly and tube, means operable by the variations of air pressure in said tube due to road inequalities for op erating said pump, in one directiomand a springy for operating said pump in the opposite directionl 2. The combination with a vehicle wheel having a felly,'of a tire formed of an annular air tube, a pump in operative connection with said folly and tube, and means connected with one of the elements of said pump 'for normally de )teasing said tube against the pressure of t e air therein, said tube depression means being moved out of tube depressing position by the variations of air pressure in said tube due to road inequalities in the movement of said Wheel.

3. The combination with a vehicle wheel having a felly, of atire formed of an an nular air tube, a ump shell mounted on said felly, a piston m said shell in operative connection with said tube, and a leaf spring bearing on said felly and normally depressing said tube at its point of connection with said piston.

4. The combination with a vehicle wheel having a Alelly, of a tire formed of an annular tube, a pump shell mounted on said telly and provided-with an inwardly o ening valve, a piston in said shell providedv with an inwardly opening valve, a tube for `nular tube, a

operatively connectin said piston with said annular tube, and a feat spring bearing on s'aid felly and normally depressing said annula; tube at its point 'of connection with said piston tube.

5. he combination withra vehicle wheel having a felly, of a tire formed of an annular tube, a pump shell mounted on `said felly, 'an inwardly openin valve therein, a cylinder slidable'in said s ell, an inwardly opening valve in s'aid cylinder, a tube projected into said shell and secured to said annular tube to lead air thereto, means for packing said cylinder in said shell, an inwardl opening valve in said tube within said s ell, and a leaf spring interposed between said felly and annular tube and normally depressing the latter at its oint of connection with said air leading tu e.

6. The combination with a vehicle wheel having a felly, of a tire formed o f an anpump shell on said, felly, an inwardly openm valve therein, a cylinder slidably mounte in said shell and closely engaging the walls thereof, an inwa'idly opening valve in said cylinder, a spring for moving said cylinder toward said tire, a tube secured to said annular tube to lead air thereto projected into said shell, an inwardly opening valve in the outer end of said tube, and a leaf spring interposed between said felly an "annular tube to 'loy normally depress the latter and hold the valved'tube awayfrom the valved end of said lshell.

In testimony-whereof I have signed my name to this specification in the presence of two subscribilng witnesses.

HENRY F. MOLKENBUR. Witnesses: THEO'poBE Aicmmn', Ema' L. AICHELE. 

